Being able to deploy one's own positioning system, independent of the GPS, can be useful in situations where the normal GPS signals are either blocked/jammed (military conflicts), or simply not available (exploration of other planets).
For planetary exploration, research being conducted at facilities including NASA Ames Research Center and Stanford University (see link at bottom) may allow a rover to deploy an array of pseudolites with no particular accuracy and still calibrate the system to centimeter-level resolution without human assistance. This would aid a rover's path-finding routines and increase the safe maneuvering speed of the unassisted vehicle. The concept is sometimes referred to as a Self-Calibrating Pseudolite Array, or SCPA.
Other applications of pseudolite arrays include precision approach landing systems for aircraft and highly accurate tracking of transponders.
Rover, go your own way: Self-Calibrating Pseudolite Array.(Mars Navigation)(Stanford University Aerospace Robotics Laboratory)
Jun 01, 2004; Future Mars rovers may use a self-deployable Pseudolite-based navigation system--without a satellite constellation--to...
Wipo Publishes Patent of Snu R&db Foundation, Kee Chang Don, So Hyoung Min, Kim Chong Won for "Pseudolite-Based Navigation System" (South Korean Inventors)
Sep 04, 2012; GENEVA, Sept. 4 -- Publication No. WO/2012/115482 was published on Aug. 30. Title of the invention: "Pseudolite-BASED...